This invention pertains to a two axis electrically powered robot wrist.
One particular type of robot having two jointed links pivoting about parallel vertical axes is illustrated in U.S. Pat. No. 4,392,776 assigned to Westinghouse Electric Corporation. U.S. patent application Ser. No. 635,375 filed July 27, 1984, now abandoned, and continuation application Ser. No. 892,890, filed July 29, 1986 which is assigned to Westinghouse Electric Corporation, discloses an improved drive system for that general type of robot. Neither the patent nor the application treat in any detail the particular type of wrist carried by the second arm of the devices. However in the commercial version of the device the end effector carried by the wrist has rotary motion imparted to it through a gearing arrangement driven by a DC motor in the second arm, while translational motion of the end effector is accomplished through a pneumatic drive.
The present invention, which has as its assignee the wholly-owned subsidiary of Westinghouse Electric Corporation, is intended to provide an improvement of the previous wrist in a number of respects which will be noted hereinafter.